Treatment of hides and skins for manufacture into leather



Patented Jan. 19, 1925.

' noneLAs MoCANDiISI-I, on

- VTREATQMENT on HIDEsAilTi) skins Fen, MANUFACTURE Intro LEATHER.

No Drawing-.1

To: all whoop it may concern:

, LIsI-r and lVIL rAM, REARDEN Amt-IN} reside ing, respectively, at Portland GateiHouse;

PortlandGate, Leeds in the county of.

York vand Kingdom of. England, .andiAshjg field, :High Street, Heckmon'dwike, in the" county of York and Kingdom'of England; 1

'eratedby exposing them ,to the action of auto-digestedyeast dissolved orsuspended have; invented new I and '-,usefiil'i Improve 'm'ents lnor Relatlng to the Treatment of Hidesi and Skins forv Manufacture into Leather' ofwhich thefollowing is a specie manner at present in use in tannery prac fication.

This invention relates to improvements in the treatment 01": hides,'liips,' and slzi ns for manufacture into leather.

Hitherto it has been: proposed to use'soa" lutions of tryptase such as are obtainedfrom animal pancreas for softening, un-

hairing and bating raw hi'des kip s and skins,-*all of whichlare hereinafter termed 'i and included in'the e i i the purpose of removing the hairs and dirt;

The action haspreferablybeen assis'ted'by preliminary treatment with an alkalinesolution; and amino-acids have also been added. ,7 u j The object of this invention is to employ yeast,-'after undergoing auto-digestion;-

or preparations of such auto-digestedyeast instead of pancreas-tryptase' for treating hides and skins forfithe softeningof dried hides; the removal-of hair from all? types of hides;and for bafiing o-r peering" of The I auto-digested prepared from yeast" obtained in the roc.- ass-of brewing, distilling malt, and other materials for the production 'of'beer, spirits. andiot'her like feririentedor distilled 110 uor's'; Preparationsof auto-digested yeasts may also be employed."

Accordingto this-invention yeast aft'e'r undergoing auto digestion and used, or 5 *about' the hereinafter named proportions has been foundto be capable of loosening the hair on hideaand at the same time will remove certain" c oiistituents'from the hides which are usually eliminated in'thebating. d or p'uering operations. The'hair onfrefsh hideo'r hides which has or liave beenp're treated*wv ith* acids or" alkalie's; when si'tbf je'cted to that-action of the auto=digested yeast,-'-is loosened in aeomparatively short time soithatitniay be removed by the vordinary methods employed in ta-I'fnery practice. 5 p 7. c r

In carryi jg this invention into practice we. proceed ;ol1owfs,- namely f I The softening; of dr'ied, hides is accelin watenf The hides may or may not have rec'elved a preliminaryssoaking, in the ;'usual tice. The addition of, a reagent capable of swellinghide substance say, formic acid;

yeast, forv eXample i v Formula N041 fgr softenz'nj 7 One hundred (100) .pounds,'+'-ayoirdupois,dried; hides are softened by soaking in a suitable vat of. container in which isplaced'a'soluti'on of about; two (2) pounds" of auto-digested yeastlt'oiivlii'c'h i'sad'ded, I about,=say one pound of formic acid, and

one hundred (100) gallons of water. I

c The lhides are allowed" tosteep inthis' solution about twentynour 'to' forty-eight hours, I 1 hen angalkali' i's 'i employed in "placeo'f as an exampl'e,.+i'sj used, namely I o lcp nd of d11-iai hides 1 g 7 Two pounds" of auto-digested:yeast,

On'e fourth )"poun'dof sodium 'bica'r a e; id-

One-hundred;( 100) gallons of'water.

the "formula No; may be" Qn'e Two (2") pounds of auto-digested yeast,

01' when a" salt is"used,' asfan example,

gen phosphate and"= 1 i One hundr'e'd "(100); gallonsof water.

e5 7 an acid then the" following formula N01 23- hundred 1x100 pounds of dried? For the-remoi alfo f hair or wool from the hides, eithei n" their normal statatr which have sar patreaae with acid or an The hides are allowed to remain in the.

solution until the hair is loosened. After removing the hair or wool, the hide or skin will have the characteristics of a bated or puered pelt.

The bating or puering operation may be carried out when required equally as well upon hides from which the hair or Wool has been previously removed by methods ordinarily and commonly employed in the tanning trade.

For example, hides,that have been ordinarily treated,after removal of hair by, say, the liming process will require to be washed, and partially neutralized before being exposed to the action of the autodigested yeast in a paddle wheel or vat of the type generally employed for the purpose, using about three (3) parts of autodigested yeast to each one hundred (100) parts of pelt.

The just named processes may be carried out with or without the addition of an activator,such as an ammonium salt,to stimulate the action of the auto-digested yeast in concentration, of about one (1) pound in fifty (50) gallons of water.

The above named weights and quantities may be varied as circumstances require, and consequently are to be treated as examples from which satisfactory results may be ob tained.

lVe are aware that it has been proposed to soak dried or dry-salted hides, kips or skins in a liquor comprising water and negative polyvalent ions produced by one or more salts, containing polyvalent radicles,such salts being sodium citrate, potassium ferrocyanide, sodium ferrocyanide, and sodium pyrophosphate,-in water, the salt in the concentrations named being capable of dispersing serum albumen which has been coagulated by heat, but are incapable of tanning the pelt; a bating liquor containing one or more enzymes of animal or vegetable origin capable of emulsifying fats or peptonizing albuminoid substances together with one or more antiseptic substances such as, salicylic acid has been used to the exclusion of any other fermentative or bio chemical action; hides and skins have been soaked, after the de-hairing process in a solution of sulphur and a carbohydrate in process of fermentation; there has been also introduced into the bath some specific ferment namely yeast to ensure the fermentation of the carbohydrate; hides and skins have been treated prior to tanning with a lipolytic bath of vegetable origin in presence of an agent which promotes lipolytic action, the bath having an acid reaction preferably derived from an organic acid, such as, butyric or lactic acid; the promotive agent may be a lipase-activator or a fat emulsifying agent.

The above methods differ from that described in this specification in that the enzymes liberated by the autolysis or digestion of the yeast, are the active agents in the latter. In this digested form the yeast is incapable of fermenting carbohydrates as described above. Yeasts in their undigested form have also been used for the acid fermentation of carbohydrates, producing such acids as lactic, butyric, and the like, which facilitate the removal of alkali from hides, and also serve to regulate the lipolytic activity of the infusions mentioned above. The use of yeast under any of the last just mentioned conditions is not contemplated. lntil the enzymes are liberated from the yeast by auto-digestion or possibly by mechanical or physical means, they are incapable of causing the changes in hides which are herein claimed.

By the phrase a reagent capable of swelling hide substance as employed in the fore going description and following claims is to be understood various substances well known to the trade by such designation and examples of which have been previously pointed out.

'What we claim is 1. The treatment of hides, kips and skins for the manufacture of leather consisting in subjecting them to the action of a solution of water and an auto-digested yeast;

2. The treatment of hides, kips and skins for the manufacture of leather consisting in subjecting them to the action of a solution of water, an auto-digested yeast and an activator for stimulating the action of the yeast.

3. The treatment of hides, kips and skins for the manufacture of leather consisting in subjecting them to the action of a solution of water, an auto-digested yeast and an ammonium salt.

4. The treatment of hides, kips and skins for the manufacture of leather consisting in subjecting them to the action of a solution of water, an auto-digested yeast and a reagent capable of swelling a hide substance.

5. The treatment of hides, kips and skins for the manufacture of leather consisting in subjecting them to the action of asolution of water, an auto-digested yeast, and an acid reagent capable of swelling a hide substance.

6. The treatment of hides, kips'; and skins; reagen capable of swelling a hide substance, 1 for the manufacture of leather consistingin and an, ammonium salt. 7 subjecting them to the. action of S QllltiOIl 8; The ti'eatment of hides, kips and skins of water, an auto-digested yeastand formic for the manufactureof 1eathe1iconsisting in 5 acid. V r subjecting them to the action ofa solution I 7 The treatment of hides, kipsand skins of water, an autordigested yeast, formic 1 for the manufacture of'leather consisting in I acid,-an'd an ammonium salt. 1 subjecting them to the action of a solution DOUGLAS MoCANDLISI-I.

of Water, an auto-digested yeast, an acid WILLIAM REARDEN ATKIN. 

